One conventional rolling apparatus is described in U.S. Pat. No. 6,457,903 which has a mobile main frame and at least a pair of undercarriages attached to the main frame in side by side relationship wherein each undercarriage has one or more smoothing rollers and there is further provided a control arm or plate pivotally attached to the main frame about a horizontal axis wherein each undercarriage is pivotally attached to the control arm or plate. There was further provided a transmission interconnecting each undercarriage to an operating lever or joystick wherein actuation of the operating lever or joystick causes reciprocatable pivotal movement of each undercarriage such that in use the or each smoothing roller closely follows ground contours.
It is important in rolling of golf greens or bowling greens that smoothing or idler rollers as described in U.S. Pat. No. 6,457,903 closely follow ground contours. If such is not the case the smoothing rollers may leave indentation lines or unsightly marks on the greens and this was detrimental to achievement of a smooth and even grass surface. Another problem of using smoothing rollers that did not closely follow ground contours was that surface corrugations in the greens still remained after repeated roller operations.
However while this objective was achieved in U.S. Pat. No. 6,457,903 by the use of pivotal movement of each undercarriage to closely follow surface undulations or corrugations it will be appreciated that U.S. Pat. No. 6,457,903 still incorporated a conventional drive roller shaft which was provided with a pair of stub axles at each end thereof which were attached to mounting plates rigidly attached to the chassis of the rolling apparatus. Each stub axle was also mounted in bearing carriers carrying bearings for each stub axle so as to enable the drive roller to rotate relative to the chassis. Another conventional arrangement was that the drive roller was rigidly mounted to a support shaft which extended through each end of the drive roller thereby providing the pair of stub axles. However these conventional drive roller mounting arrangements had disadvantages in that (i) on uneven ground there was created greater ground pressure resulting in an uneven surface finish due to lines, marks or impressions left on the ground surface after passage of the drive roller. Other disadvantages were (ii) that the drive roller had reduced width compared to each smoothing roller, (iii) that there was less driving friction on the ground than desired which created loss of traction in certain driving conditions and situations, especially on increased slopes or wet turf and (iv) the drive roller was rigidly mounted to a support shaft which meant that the style of roller to be employed was limited being relatively short which was not adapted to follow ground contours.
It was also to be appreciated that in relation to each of the smoothing rollers in order to achieve an objective of each smoothing roller closely following ground contours it was necessary to mount a plurality of smoothing rollers in undercarriages as described above and this procedure was relatively complicated although it operated in a perfectly satisfactory manner.